1. Field of Invention
The present invention relates to a junction box to connect and distribute multiple wiring harnesses in a vehicle or the like
2. Description of Related Art
In a conceivable junction box for a vehicle, a wiring plate in which single-layer or multi-layer wiring boards are stacked, and a control board fitted with electronic components such as electronic elements, resistors, coils, relays and fuses, are loaded parallel to each other and connected with respective terminals.
Since the control board is loaded parallel (so-called xe2x80x9cflatwaysxe2x80x9d) to the wiring plate, large area over the wiring plate is occupied by a required space for fitting the control board thereon, and the wiring plate and the junction box is eventually enlarged.
Moreover, by the flatways connection, relay terminals or connectors are required to connect bus bar terminals extending out of mutually opposing faces thereof. The number of the relay terminals or the connectors is required to be equal to that of the bus bar terminals, whereby the number of components and assembling steps are increased.
The object of the present invention is to provide a junction box, which is compact and simply assembled, with a less space on a wiring plate for mounting a control board thereon and with fewer components for connecting the control board to the wiring plate.
A first aspect of the present invention is a junction box comprising: a casing; and a junction box body housed in the casing, wherein the junction box body comprises a first board having a conducting member to form a circuit thereon; second and third boards mounted on the first board, respectively including a circuit formed thereon to be connected to the circuit of the first board; and a cover for housing the first, second and third boards, wherein the third board includes a substrate, a terminal block fitted on the substrate; and a conductor connected to the circuit of the third board, and provided with a pressure terminal extending out of the terminal block, the pressure terminal for penetrating through the first board to be connected by solderless connection to the conducting member of the first board.
Preferably, the substrate of the third board is mounted substantially perpendicular to the first board, and the conducting member of the first board is arranged to form the circuit on a face opposite to a face thereof on which the second board is mounted.
And preferably, the second board includes a bus bar to form the circuit thereof, and the bus bar is provided with a pressure terminal for penetrating through the first board to be connected by solderless connection to the conducting member of the first board.
And preferably, the terminal block is configured with a face perpendicular to the substrate, and the pressure terminal of the conductor extends out of the face in a direction parallel to the substrate.
According to the first aspect of the present invention constituted as described above, upon mounting a control board (as the third board) onto a wiring plate (as the first board), connection between the control board and the circuit of the wiring plate is achieved simply by training an orthogonal face (as the face perpendicular to the substrate) of the terminal block to a face of the control board upon the wiring plate, by allowing the pressure terminal of a lead terminal (as the conductor) extending from the orthogonal face to penetrate through the wiring plate, and by solderless connection of the pressure terminal to an electric wire (as a conducting member) which is cabled on the opposite face of the wiring plate. Since the pressure terminal of the lead terminal extends out of the terminal block in a direction parallel to the substrate of control board, the control board is mounted perpendicularly on the wiring plate by solderless connection.
A second aspect of the present invention is the junction box according to the first aspect, in which the terminal block of the third board is divided in a longitudinal direction thereof into divided blocks, and adjacent end portions of the respective divided blocks are mutually superimposed to be fastened integrally to the first board.
According to the second aspect of the present invention constituted as described above, a superimposed portion of the end portion of the respective divided blocks are integrally fastened to the wiring plate. Therefore, the number of fasteners is reduced in comparison with a case of fitting both end portions of the terminal block severally onto the wiring plate, whereby assembling steps are reduced. Moreover, since adjacent terminal blocks can be integrated, the whole terminal blocks can be positioned accurately.
A third aspect of the present invention is the junction box according to the first aspect, in which the conductor penetrates the terminal block and the substrate, and has a bent portion exposed in a position between the terminal block and the substrate.
Preferably, an end portion of the conductor penetrating the substrate is soldered to the circuit of the third board.
According to the third aspect of the present invention constituted as described above, a direction of the pressure terminal can be orthogonal to a direction of the end portion of the lead terminal penetrating the substrate to be soldered onto the circuit of the control board, and it is possible to prevent load generated upon connecting, by solderless connection, the pressure terminal to the electric wire of the wiring plate to be directly transferred onto a soldered portion owing to flexure of the lead terminal.